David Cicilline actually said...

I strongly support the establishment of an Ambassador over cyberspace at the State Department.

He needs to come back again and take the same oath and be directed by the chairman to answer the questions of the committee.

It's very unusual. This is pattern for the attorney general. He comes before a committee. He takes an oath to testify truthfully and fully.

Witnesses don't get to pick and choose what they want to answer.